Multiple entries in Boot loader menu

ok, i have a big problem. it started the first time i tried to format my computer, insted of booting from cd, i installed windows exp ( home edition ) from my desktop. now every time i turn my computer on it comes up as a black screen and asks me which program to use
- windows exp
- windows exp
i want to know if i can get rid of it so when i turn on my computer, it just loads normally into the one windows exp ( the 2nd windows exp doesnt work...) another problem is, now i cant format my comp because of this, because when u put the windows exp cd and boot from disk, it doesnt do that anymore it just goes straight to the operating system and asks me what windows exp to use.
i know this sounds real confusing, but i really need help please!
thank you for your time.